Which parts fail
Components named in complaints (battery, alternator, wiring, ignition, instrument cluster, infotainment).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2005 Hummer H2 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2005 Hummer H2. The contact stated that while parking in the mountains, the vehicle was in the park position, and it unexpectedly rolled and stopped at a boulder. There were no warning lights illuminated. The door hit the driver and knocked him to the ground, and he sustained an injury to his head, but medical attention was not provided. Another person on an ATV provided a jump start, but the vehicle failed to restart. The contact walked several miles to get assistance. The contact was able to view YouTube and replace the part. The contact stated that the transmission shifter cable had failed. There was a hole in the shaft connected to the transmission to the C clip. The local dealer was contacted, but the vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 111,400.
Driving home I began to smell and electrical burning smell. It began very quickly and came and went for about 2 miles. I pulled over and looked and could not see smoke or fire so I continued home. I drove the remaining 4 miles to my home and immediately got my husband to check as the cab had filled with the smell of an electrical fire. He located the area the smell was strongest and then watched as smoke came out. He unbolted the windshield washer fluid tank and the motor on bottom had actually burned, melted and was on the verge of causing some serious damage. The wipers were not being used and had not been touched. This vehicle is equipped with a heater for the fluid.
Car will not start due to pass-lock or other malfunction component. Must try and fail and then wait for car to 're-set' each and every time the vehicle is tried to be started. After 10 minutes the car's engine completely kills, even if car is in motion. Reprogrammed keys and this only worked for a week. Now each and every door lock, back hatch lock, etc... Has failed. The hatch is locked closed and the doors will only unlock or lock physically with your hand. The speedometer fails intermittently, along with other gauges working only sometimes.
Tl* the contact owns a 2005 Hummer H2. The contact stated that the driver side heating element turned on without warning and failed to turn off. The vehicle was taken to dealer three times, where it was diagnosed that the driver seat module needed to be reprogrammed. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 48,000.
Heater fan control knob overheats. When heater was in operation the heater control knob area above and below the cvery hot to the touch, heating up radio and other front dash components. Prior to this, instrument panel gauges stopped working completely for gas gauge and rpms, and stops working intermittently for speedometer (occurred around 100K miles).
Heater fan blower motor started working intermittently while car in motion, then smell of burning electrical. Wiring harness to heater under the glovebox was burning hot to the touch and melted all the wires. Plastic wire harness component completely destroyed and almost caught fire.
In the midst of traveling on vacation, the speedometer and many of the other dash components just quit working. I had to rely solely on the portable GPS to determine the speed that I was going. This is unsafe, and this is an issue that Hummer most certainly needs to correct.
While traveling on the main roads the speedometer intermittently malfunctions then drops to zero, whereas I'm literally unable to determine my speed this seems to occur when the engine warms up and I been driving for better than a half hour.
Get in start the vehicle, seat heat comes on. I turn it off it comes back on seconds later. It will not go off and stay off. It does not matter if im driving or parked. Seat heat comes on by its self.
I started my vehicle 4 days ago and the speedometer and gauges were frozen and did not operate at all. I drove to the store and the gauge remained at 0 the entire time. When you accelerate the speedometer does not move from 0 MPH. I turned the vehicle off and turned it back on and there was no change. Yesterday when I started the vehicle the gauge would only move between 30-50 MPH. Today when I started the vehicle it is frozen at 120 MPH and the khm(?) does not move past 1.when I accelerate neither of the two gauges are functioning. I have yet to repair it bc it has happened just a few days ago but I was told that I am looking at a very large repair cost to replace the entire dashboard cluster. The same thing happened in my 2003 model and I sold the vehicle. As well the rear suspension is lowering on its own to the lowest position and does not go back to the normal height. …
Electrical complaints in other H2 years
Frequently asked questions
How common are electrical problems on the 2005 Hummer H2?
NHTSA has 27 complaints about the electrical system of the 2005 Hummer H2, 34% of the model year's 79 complaints. The component named most often is instrument cluster/panel (4 mentions).
Is there a recall for 2005 Hummer H2 electrical problems?
No. NHTSA lists no electrical system recall for the 2005 Hummer H2, though it has 2 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2005 Hummer H2 electrical problems start?
Half of the complaints with a recorded mileage happened before about 52,000 miles, and 13% before 25,000 miles.
Is it dangerous?
Owners linked 0 crashes, 1 fire and 2 injuries to electrical system problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.